libafsrpc: Assemble with libtool

libafsrpc: Assemble with libtool

Use libtool to assemble the libafsrpc shared and static libraries
from objects built with libtool in each of the directories that
contribute to the library (fsint, rx, rxkad, comerr, util, rxstat,
sys and lwp).

Each source directory controls which objects are built into the shared
library by making a libafsrpc_<dir> libtool convenience directory. These
convenience directories are then merged together to produce the
libafsrpc library.

Change-Id: I330aeb8df4c237b408a298826363eea7357339ce
Reviewed-on: http://gerrit.openafs.org/8072
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>